//
// Authors:
//   Atsushi Enomoto
//
// Copyright 2007 Novell (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
#if NET_2_0

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Xml;

using XPI = System.Xml.Linq.XProcessingInstruction;

namespace System.Xml.Linq
{
	public abstract class XNode : XObject
	{
		public static int CompareDocumentOrder(XNode n1, XNode n2)
		{
			return order_comparer.Compare(n1, n2);
		}

		public static bool DeepEquals(XNode n1, XNode n2)
		{
			return eq_comparer.Equals(n1, n2);
		}

		static XNodeEqualityComparer eq_comparer =
			new XNodeEqualityComparer();
		static XNodeDocumentOrderComparer order_comparer =
			new XNodeDocumentOrderComparer();

		XNode previous;
		XNode next;

		internal XNode()
		{
		}

		public static XNodeDocumentOrderComparer DocumentOrderComparer
		{
			get { return order_comparer; }
		}

		public static XNodeEqualityComparer EqualityComparer
		{
			get { return eq_comparer; }
		}

		public XNode PreviousNode
		{
			get { return previous; }
			internal set { previous = value; }
		}

		public XNode NextNode
		{
			get { return next; }
			internal set { next = value; }
		}

		public string ToString(SaveOptions options)
		{
			StringWriter sw = new StringWriter();
			XmlWriterSettings s = new XmlWriterSettings()
			{
				ConformanceLevel = ConformanceLevel.Auto,
				Indent = options != SaveOptions.DisableFormatting,
				OmitXmlDeclaration = true
			};
			XmlWriter xw = XmlWriter.Create(sw, s);
			WriteTo(xw);
			xw.Close();
			return sw.ToString();
		}

		public void AddAfterSelf(object content)
		{
			if (Owner == null)
				throw new InvalidOperationException();
			XNode here = this;
			XNode orgNext = next;
			foreach (object o in XUtil.ExpandArray(content))
			{
				if (o == null || Owner.OnAddingObject(o, true, here, false))
					continue;
				XNode n = XUtil.ToNode(o);
				Owner.OnAddingObject(n);
				n = (XNode)XUtil.GetDetachedObject(n);
				n.SetOwner(Owner);
				n.previous = here;
				here.next = n;
				n.next = orgNext;
				if (orgNext != null)
					orgNext.previous = n;
				else
					Owner.LastNode = n;
				here = n;
				Owner.OnAddedObject(n);
			}
		}

		public void AddAfterSelf(params object[] content)
		{
			if (Owner == null)
				throw new InvalidOperationException();
			AddAfterSelf((object)content);
		}

		public void AddBeforeSelf(object content)
		{
			if (Owner == null)
				throw new InvalidOperationException();
			foreach (object o in XUtil.ExpandArray(content))
			{
				if (o == null || Owner.OnAddingObject(o, true, previous, true))
					continue;

				XNode n = XUtil.ToNode(o);
				Owner.OnAddingObject(n);
				n = (XNode)XUtil.GetDetachedObject(n);
				n.SetOwner(Owner);
				n.previous = previous;
				n.next = this;
				if (previous != null)
					previous.next = n;
				previous = n;
				if (Owner.FirstNode == this)
					Owner.FirstNode = n;
				Owner.OnAddedObject(n);
			}
		}

		public void AddBeforeSelf(params object[] content)
		{
			if (Owner == null)
				throw new InvalidOperationException();
			AddBeforeSelf((object)content);
		}

		public static XNode ReadFrom(XmlReader reader)
		{
			return ReadFrom(reader, LoadOptions.None);
		}

		internal static XNode ReadFrom(XmlReader r, LoadOptions options)
		{
			switch (r.NodeType)
			{
				case XmlNodeType.Element:
					return XElement.LoadCore(r, options);
				case XmlNodeType.Whitespace:
				case XmlNodeType.SignificantWhitespace:
				case XmlNodeType.Text:
					XText t = new XText(r.Value);
					t.FillLineInfoAndBaseUri(r, options);
					r.Read();
					return t;
				case XmlNodeType.CDATA:
					XCData c = new XCData(r.Value);
					c.FillLineInfoAndBaseUri(r, options);
					r.Read();
					return c;
				case XmlNodeType.ProcessingInstruction:
					XPI pi = new XPI(r.Name, r.Value);
					pi.FillLineInfoAndBaseUri(r, options);
					r.Read();
					return pi;
				case XmlNodeType.Comment:
					XComment cm = new XComment(r.Value);
					cm.FillLineInfoAndBaseUri(r, options);
					r.Read();
					return cm;
				case XmlNodeType.DocumentType:
					XDocumentType d = new XDocumentType(r.Name,
						r.GetAttribute("PUBLIC"),
						r.GetAttribute("SYSTEM"),
						r.Value);
					d.FillLineInfoAndBaseUri(r, options);
					r.Read();
					return d;
				default:
					throw new InvalidOperationException(String.Format("Node type {0} is not supported", r.NodeType));
			}
		}

		public void Remove()
		{
			if (Owner == null)
				throw new InvalidOperationException("Owner is missing");

			var owner = Owner;
			owner.OnRemovingObject(this);
			if (Owner.FirstNode == this)
				Owner.FirstNode = next;
			if (Owner.LastNode == this)
				Owner.LastNode = previous;
			if (previous != null)
				previous.next = next;
			if (next != null)
				next.previous = previous;
			previous = null;
			next = null;
			SetOwner(null);
			owner.OnRemovedObject(this);
		}

		public override string ToString()
		{
			return ToString(SaveOptions.None);
		}

		public abstract void WriteTo(XmlWriter writer);

		public IEnumerable<XElement> Ancestors()
		{
			for (XElement el = Parent; el != null; el = el.Parent)
				yield return el;
		}

		public IEnumerable<XElement> Ancestors(XName name)
		{
			foreach (XElement el in Ancestors())
				if (el.Name == name)
					yield return el;
		}

		public XmlReader CreateReader()
		{
			return new XNodeReader(this);
		}

#if NET_4_0
		public XmlReader CreateReader (ReaderOptions readerOptions)
		{
			var r = new XNodeReader (this);
			if ((readerOptions & ReaderOptions.OmitDuplicateNamespaces) != 0)
				r.OmitDuplicateNamespaces = true;
			
			return r;
		}
#endif

		public IEnumerable<XElement> ElementsAfterSelf()
		{
			foreach (XNode n in NodesAfterSelf())
				if (n is XElement)
					yield return (XElement)n;
		}

		public IEnumerable<XElement> ElementsAfterSelf(XName name)
		{
			foreach (XElement el in ElementsAfterSelf())
				if (el.Name == name)
					yield return el;
		}

		public IEnumerable<XElement> ElementsBeforeSelf()
		{
			foreach (XNode n in NodesBeforeSelf())
				if (n is XElement)
					yield return (XElement)n;
		}

		public IEnumerable<XElement> ElementsBeforeSelf(XName name)
		{
			foreach (XElement el in ElementsBeforeSelf())
				if (el.Name == name)
					yield return el;
		}

		public bool IsAfter(XNode node)
		{
			return XNode.DocumentOrderComparer.Compare(this, node) > 0;
		}

		public bool IsBefore(XNode node)
		{
			return XNode.DocumentOrderComparer.Compare(this, node) < 0;
		}

		public IEnumerable<XNode> NodesAfterSelf()
		{
			if (Owner == null)
				yield break;
			for (XNode n = NextNode; n != null; n = n.NextNode)
				yield return n;
		}

		public IEnumerable<XNode> NodesBeforeSelf()
		{
			if (Owner == null)
				yield break;
			for (XNode n = Owner.FirstNode; n != this; n = n.NextNode)
				yield return n;
		}

		public void ReplaceWith(object content)
		{
			if (Owner == null)
				throw new InvalidOperationException();

			XNode here = previous;
			XNode orgNext = next;
			XContainer orgOwner = Owner;
			Remove();
			foreach (object o in XUtil.ExpandArray(content))
			{
				if (o == null || orgOwner.OnAddingObject(o, true, here, false))
					continue;
				XNode n = XUtil.ToNode(o);
				n = (XNode)XUtil.GetDetachedObject(n);
				n.SetOwner(orgOwner);
				n.previous = here;
				if (here != null)
					here.next = n;
				else
					orgOwner.FirstNode = n;
				n.next = orgNext;
				if (orgNext != null)
					orgNext.previous = n;
				else
					orgOwner.LastNode = n;
				here = n;
			}
		}

		public void ReplaceWith(params object[] content)
		{
			if (Owner == null)
				throw new InvalidOperationException();
			ReplaceWith((object)content);
		}
	}
}

#endif